The present disclosure relates to solenoid ball valves and bypass orifices thereof
Many different types of valves are used to control a variety of fluids and in a variety of ways. Depending on the application, fluid flow is controlled in one or more manners. Pulse-width-modulated, on/off, and variable pressure are a few coined manners of controlling fluid flow known to those of skill in the art. To assist in control of fluid flow, solenoid (i.e., electrically actuated) valves that include electrical systems are often used due to their ability to efficiently and effectively control fluid flow in a variety of ways.
Specifically, on/off solenoid valves are used in many applications. For example, solenoid valves are useful in controlling the flow of hydraulic fluid in, for example, drive train systems of motor vehicles. A drive train system is that which transfers power from the engine to the wheels. It includes the clutch or torque converter, the transmission, differential, ring and pinion gears, axles, and where applicable drive shaft(s) and transfer case, universal and/or CV-joints. Within the drive train system, individual components can operate using a solenoid valve. During operation, an electronic controller provides an electrical signal to the solenoid valve, which then provides a corresponding pressure signal to a pressure actuator for effecting a desired movement of an associated component.
Generally, solenoid valves typically include at least a supply port (also referred to as an “inlet port”) and a pressure control output port, which provide respective fluid flow to and from a valve's housing for operation of an external component in fluid communication therewith. The internal valve mechanics of solenoid valves vary widely within the valve housing.
One type of on/off solenoid valve comprises a ball valve having an inlet port, a pressure control outlet port, and an exhaust port through which fluid is discharged to a sump or is returned to rejoin the fluid supply. Such valves provide electrical control of a fluid pressure by controlling the flow of fluid from the inlet port to a valving chamber within the valve housing in an on/off manner. The valving chamber in these valves is in operable communication with the pressure control outlet port.
A desired pressure at the pressure control outlet port is generated by controlling the amount of fluid bleed to the exhaust port in relation to the fluid exiting the valving chamber via the pressure control outlet port. Conventionally, in ball valves of the on/off type, particularly those with controlled fluid flow between the pressure control outlet port and exhaust port (e.g., by placement of a flow control valve, such as a check valve, therebetween), pressure is generated at the pressure control outlet port only when the valve is in an “on” position. This occurs because the inlet port is only open for fluid flow to the valving chamber when in the “on” position.
Implicitly, ball valves include a ball disposed in the valving chamber, whereby the ball moves with respect to a valve seat that's adjacent to the inlet port. The ball moves via an operating rod mechanism disposed between the ball and a solenoid armature operating in response to an electric signal. In this arrangement, two electrical states are typically used—one for opening the valve, and one for closing the valve. Ball valves can provide many advantages over standard solenoid valves, some of which include, for example, higher permissible flow rates, lower resistance to flow resulting in a lower pressure drop across a valve, higher permissible pressure ratings, compatibility with a wide range of media, no minimum pressure requirements (differential pressure), and smoother operation (reducing water hammer). However, there is a continuing need for maximizing and improving the advantages offered by ball valves.
Although ball valves often provide smoother operation than other types of solenoid valves, there is a need to eliminate or, at a minimum, reduce turbulence within the valving chamber of such valves during operation. It is known that the presence of turbulence within solenoid valving chambers is a contributing factor in variable valve performance. As can be appreciated, reliable and predictable performance is highly desirable. Thus, on/off solenoid ball valves with improved reliability and performance are desired.
In addition, the ability to extend the applicable range of on/off solenoid ball valves is also desired. Conventional use of on/off solenoid ball valves is limited in certain applications. One such application is that requiring maintenance of a minimum pressure at the pressure control outlet port, irrespective of whether the valve is in the “on” or “off” position. Generally, those desiring this type of operation have been forced to utilize valves other than on/off solenoid ball valves for that purpose.
When using other types of valves, pressure may be generated at the pressure control outlet port during all positions of operation. For example, due to their design, spool valves inherently allow fluid leakage to the pressure control outlet port at all positions of operation. However, adequate control of this fluid leakage to obtain desired pressure levels at the pressure control outlet port has challenged those in the art. Therefore, alternative valves are desired. Due to the many benefits offered by solenoid ball valves, it would be highly desirable to utilize improved solenoid ball valves with enhanced applicability.